SRC/zppcon.f(3)

NAME
SRC/zppcon.f

SYNOPSIS

  Functions/Subroutines
subroutine zppcon (uplo, n, ap, anorm, rcond, work, rwork, info)
ZPPCON

Function/Subroutine Documentation

  subroutine zppcon (character uplo, integer n, complex*16, dimension( * ) ap, double precision anorm, double precision rcond, complex*16, dimension( * ) work, double precision, dimension( * ) rwork, integer info)

ZPPCON

Purpose:

    !>
    !> ZPPCON estimates the reciprocal of the condition number (in the
    !> 1-norm) of a complex Hermitian positive definite packed matrix using
    !> the Cholesky factorization A = U**H*U or A = L*L**H computed by
    !> ZPPTRF.
    !>
    !> An estimate is obtained for norm(inv(A)), and the reciprocal of the
    !> condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
    !>

Parameters
    UPLO

    !>          UPLO is CHARACTER*1
    !>          = 'U':  Upper triangle of A is stored;
    !>          = 'L':  Lower triangle of A is stored.
    !>

    N

    !>          N is INTEGER
    !>          The order of the matrix A.  N >= 0.
    !>

    AP

    !>          AP is COMPLEX*16 array, dimension (N*(N+1)/2)
    !>          The triangular factor U or L from the Cholesky factorization
    !>          A = U**H*U or A = L*L**H, packed columnwise in a linear
    !>          array.  The j-th column of U or L is stored in the array AP
    !>          as follows:
    !>          if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
    !>          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.
    !>

    ANORM

    !>          ANORM is DOUBLE PRECISION
    !>          The 1-norm (or infinity-norm) of the Hermitian matrix A.
    !>

    RCOND

    !>          RCOND is DOUBLE PRECISION
    !>          The reciprocal of the condition number of the matrix A,
    !>          computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an
    !>          estimate of the 1-norm of inv(A) computed in this routine.
    !>

    WORK

    !>          WORK is COMPLEX*16 array, dimension (2*N)
    !>

    RWORK

    !>          RWORK is DOUBLE PRECISION array, dimension (N)
    !>

    INFO

    !>          INFO is INTEGER
    !>          = 0:  successful exit
    !>          < 0:  if INFO = -i, the i-th argument had an illegal value
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 117 of file zppcon.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.